The reason behind panic selling is that people lack patience and they get panic when they see price going down and start selling their coins at cheaper price and I think that is the time when we should hold our coins tight and wait for the price to bounce back again but generally people doesn't follow this simple rule.
It is not the patience that triggers panic selling. It is the lack of knowledge on what it is their holding. Lack knowledge meand lack of faith, and lack of faith means easily get shaken when dumps occurs, may it valid or fake dump. So the first move this people who lack faith is to sell their holdings the soonest the can.
I think both also play a role in the panic of users, believe the bitcoin will also affect. If they believe in bitcoin. Of course when the price goes down they will not easily panic
There are many people who commit stupid acts. This is mainly due to a lack of knowledge. But I have a hope that every year such alarmists in the bitcoin community will become smaller, and reasonable people more
Well we cannot blame those people who thinks that bitcoins value will go down fast and the reason why they think that bitcoin will go down in value is the experience that they had before. Possibly they invested last 2013 when the bubble of bitcoin occurs and the price from 1000$ have suddenly flowing down. That occurrence has made many people to have huge losses and thus it made them to think of bitcoin in such way.
This is the common psychology of human, we never accepts loss and when too much loss it will affect our psychology, make us panic and want to find a way out. Selling is the best way to make us feel good but this is also our stupidity because investors and traders know that, they always create traps, they make us panic selling. We can not blame anything, this is our fault because if we have no faith and no knowledge, that will make us easy to fall into the trap but this is also the experience helps us to become more mature